Snubber for hoists



May 14, 1945. E. B. 'LEAR' I SNUBBER FOR HOISTS Filed Aug. 26, 194:5

\ 2 Sheets-Sheet 1 v N R o W A INVENTOR EAR; B. LEAR B stantially online 2--2 of Fig. 1.

Patented May 14, 1946 [SNUBBER roa nois'rs Earl B.'Lear,.GariieldHeights, Ohio, asslgnor to The Cleveland, Pneumatic Tool Company,Cleveland, Ohio, a corporation'of Ohio Application August 20, 1943,Serial No. 500,107

9Cla'ims. (c1. ts-7'7) The present invention relates broadly to windingapparatusor hoists and} more particularly, to an improvedsnubber'mechanism' for the same.

The primary object of the invention resides in the provision of novelsnubbing means for a winding reel or the like which will-preventbacklash and tangling of thecable being wound thereon.

A further object of the invention is to provide a snubbing mechanismwhich may form a part of the friction member or brake of the windingreel or may be attached thereto in a manner to prevent backlash andtangling of the cable being wound on said 'reel.

tion snubber or" brake, which is normally orcontinuously'applied forpreventing backlash, is autothe gear casing I8. A tie rod It extendslongitudinally through the upper end of the bearing supports l3, ,andI5, whileother tie rods and 2| extend on opposed sides of .the hoist athrough ears extending laterally of said bearing brake drums rotate withtheir respective winding a reels. Eachpof the brakedrums has. associatedmatically released upon actuation of the clutch from a more completeexamination of this speciilcation. 1 a

. In the drawings which illustrate the invention: Fig. 1 is a sideelevational view of winding apparatus embodying the invention.

Fig. 2 is a transverse sectional view taken sub- Fig. 3 is a partialside elevation illustrating the snubber and releasingmember.

Fig. 4'is a partial side elevationof the apparatusshowninFigJ. v H

Fig. 5 is a transverse sectional view similar to Fig. 2 but illustratinga modified form of friction device. a v Fig.6 is ade tailed sectionalview of the'tension means for supporting one end of the'frlction band.Referring to the drawings for a more detailed description thereof, thereis shown a hoist generally designated by the reference numeral ehavingthe improved snubbing means embodied therein.

The hoist comprises, in general, a frame shaving thereon a driving motorIn and a pair of rotatable winding reels II and l2. The frame 9 in-'therewith a friction device 24 which encircles, or partially encircles,such brake drums.

The friction'device-.24, i i'll,this instance, comprises a brake band 25havingfriction lining-26 for cooperation wlththe surfacefof the brakedrum. It is to be understood that the brake drums 22 and 23 are eachprovidedwith a friction devicefof the character described, but forpurposes-of illustration, only one suchdevice has been shown in thedrawings at Fig. 2. .One end ofthe brake band25 is anchored to the frameSas bymeans of the eye bolt 21. which is surrounded by a'compressionspring 28 hearing at one end against the eye of I the bolt 21 and at itsother end against the frame 9. The other .end of the brake band' 25fhasa loop terminal-.25 connected'to an ear 30 forming a part of the frame9. The eye bolt 21 is associated with a brake operating mechanismgenerally designatedby the reference numeral 3| which comprises a .plate32 bolted to the frame 9 which carries an operating lever 33, one end ofwhich is in engagement with the teeth of a rack 34. The lever. 33 actsas a pedal to be depressed by the foot of the operator of the hoist forpulling the end of the:brake band secured to the eye bolt into firmengagement with the surface of the brake drum against the tension'ofspring 28 to lock'thedrum against rotation," and said brake band isthereby operated independently of the snubber mechanism to behereinafter more fully described.=

end of the band 35 has riveted or otherwise secured thereto an L -shapedplate 36 through which extends an eye bolt 3'! carried by and projectingvertically from the tie rod 20: The upper portion ofthe eye bolt 31carries a compression spring 38 which is disposed between the nut 39 andthe p1ate-36 and acts-on the eye bolt so as to continuouslyexert a pullon the band 35, tending to apply the snubber to the brake drum 22through the friction band 25'. The other end of the band 35 OFFICEcarries a looped terminal 48 adapted to receive one end M of a U-shapedconnector 42. The terminal 48 is secured to the end M by meanspf acotter key or the like 43. As shown in Fig. 2 of the drawings, theU-shaped clamp 42 is bowed so as to extend around the outer periphery ofthe tie rod 2|, and its opposite end 44 is disposed in an opening formedin a lever 45 by means of which the band 35 is held and released fromoperative engagement with the band 25. One end of the lever 45 is formedas shown at 45' to fit around the tie rod 28 and with the U-shaped clamp42 is so designed that when said lever is in the locked position shownin full lines in Fig. 2, it is just past the center axis of the tie rod2|. Slight pressure only is required to swing the lever back beyondcenter to carry it to the 'dotted line position illustrated in Fig. 2 atwhich the lever 45 will pull the band against the tension of the spring38 to firmly lock band 35 in engagement with the brake band 25. Thelever 45 is moved to the dotted line position when occasion demandsmanual unwinding of the cable from the drum. As is understood, raisingthe lever 45 will release the snubber band 35 and friction band frombraking contact with the drum, thus permitting the cable to be freelyunwound.

The hoist 8 is provided adjacent each of the brake drums 22 and 23 witha clutch drum 46 and 41, respectively, these clutch drums being rotatable on the shaft I6. Extending laterally of each clutch drum is a plate48 whichis disposed beneath the L-shaped plate 36, as more particularlyshown in Fig. 4 of the drawings. As will hereinafter appear, the plate48 acts, upon actuation of the clutch mechanism, to release the snubberso that the cable can be freely wound on the cable reels II and I2. Afriction device 49 is associated with each of the clutch drums andencircles, or partially encircles, the same. The plate 48 is carried byand extends laterally of said device 49. Each clutch drum carries one ormore spindles 50 on which the planet gears 5|, usually employed inhoists of this kind, are rotatably mounted. As shown in Fig. 2, each ofthe brake drums has an internal gear or ring gear 52 therein which isconnected with a drive pinion 53 of the shaft I6 by means of the planetgears 5|. When the winding reel I2 is to be rotated, the clutch drum 41is retarded or held stationary by the friction device 49, and thisprevents the idler gears 5i from revolving about the pinion 53 andcauses them to rotate on their spindles 58 to transmit torque from thepinion to the ring gear 52. The resulting rotation of the ring gear 52causes rotation of the brake drum 23 and the winding reel I2 connectedthereto. When the winding reel I2 is to :e slowed or stopped, the clutchdrum 41 is released and permitted to rotate, at which time the gears 5Itravel idly around the shaft I6.

The friction devices 49 associated with the respective clutch drums 46and 41, each comprises a band or the like 58 having suitable frictionlining or shoes for cooperation with the drum surfaces and having ends54 and 55 adapted to be drawn together by the lever 56 and link 51 when.the friction device 49 is to be applied to the clutch drum 41. Thefriction device 49 is disposed around the clutch drum 41 so as to becapable of limited circumferential shifting with the clutch drum whenthe friction device is applied or tightened against the surface of thedrum. This limited shifting of the friction device is utilized inloosening the snubber band 35 through the plate 48, that is by pressureexerted against L-shaped plate 36 to compress spring 38.

The snubber bands 35 are normally applied or .held in engagement withtheir respective brake bands 25 when the lever 45 is in the full lineposition shown in Fig. 2 so as to hold the winding reels againstunintentional or excessive rotation which would cause backlash ortangling of the cable. When one of the winding reels II or I2 is to berotated, its respective clutch lever 56 is actuated to apply thefriction device 49 to the clutch drum 46 or 41 to retard or stop saidclutch drum. As explained above, this results in the winding reel beingdriven from the shaft I6 through the gears 5|, 52, and 53. When thefriction device 49 is tightened against its clutch drum, it isimmediately carried or shifted circumferentially by the clutch drum, andsuch movement is transmitted by the plate 48 to the spring held end ofthe snubber band 35 in a direction to compress the spring 38 and releasethe snubber from its engagement with the brake band 25. The release ofthe snubber 35 permits the winding reel I2 to be freely driven for thedesired winding operation. When the winding reel I2 is to be stopped,the clutch lever 56 is swung in the opposite direction to release thefriction device 49, whereupon, the spring 38 immediately applies ortightens the snubber band 35 against the brake band 25, and the actionof the brake band against the brakedrum 23 will prevent over-running ofthe windin reel which would cause backlash and tangling of the cable. Inaddition to applying the snubber 35 against the brake band 25, thespring 38 also acts throughithe plate 48 to return the friction device49 of the clutch means to its initial position.

In Fig. 5 of the drawings, it will be observed that the brake band 25and its brake actuating means have been dispensed with, and the snubberband I35 is provided with a friction lining I36 which is in directengagement with the surface of the brake drum I23. One end of thesnubber band carries a plate I36 through which extends an eye belt I31carried by the tie rod I28. The compression spring I38 is supportedbetween the plate I36 and a bolt I39. The other end of the snubber bandI35 is connected'with an actuating lever I45 through the U-shaped clampMI in the manner previously described in connection with theillustration of Fig. 2. Upon operation of the clutch friction devicethrough the lever 56, the snubber band 35 acts directly against thesurface of the brake drum I23 to prevent over-running of the windingreel and thus preclude possibility of tangling'of the cable. This formof the invention is to be employed with those devices which do not use abrake operating mechanism of the type shown in Fig. 2.

It will be seen from the foregoing description and the accompanyingdrawings that there has been provided an improved winding apparatus orhoist in which a snubber for the winding reel is automatically releasedupon actuation of the clutch controlling the winding operation and isautomatically reapplied upon realease of the clutch. It will be seenalso that this automatic snubbing'action is obtained through the use ofsimplified apparatus utilizing the circumferential shifting of thefriction device of th clutch means for actuating the snubber.

Although the foregoing description is necessarlly of a detailedcharacter, in order to completely set forth the invention, it is to beunderstood that the specific terminology is not intended to berestrictive or. confining and, it is to be further understood thatvarious rearrangements of parts and modifications of structural detailmay I be resorted to without departing from the scope or spirit of theinvention as herein claimed.

I claim: 1. In apparatus of the character described, a base frame,longitudinally spaced bearing supports extending vertically from saidframe, a tie rod on each side of said bearing supports and v g with oneof said drums arjc adapted to be applied thereto to'retard rotation ofsaid one drum, a.

friction device associated with the second drum to retard rotationthereof, a member carried by and extending vertically of one of said tierods, an

L -sh'aped plate secured to one end of said second drum friction deviceand slidablylheld on said member, a tension spring on said verticallyexextending longitudinally therethrough, a pair of said second frictiondevice to the other of said tie rods, and means interconnecting saidfriction devices so that the release of said one friction deviceautomatically causes the application of the other friction device to itsdrum.

2. In apparatus'of the character described, a

base frame, longitudinally spaced bearing supports extending verticallyfrom, said frame, a tie rod on each side of said bearing supports andextending longitudinally therethrough, a pair of adjacent drumsrotatably carried by said frame within said supports, a friction deviceassociated with one of said drumsand adapted to be applied thereto toretard rotation of said one drum, a friction device associated with thesecond drum to retard rotation thereof, a member carried by andextending vertically of one of said tie rods, means projecting from oneend of said second drum friction device and slidably held on saidmember, means for placing said projecting means under tension, means forreleasably attaching. the other end of'said second friction device tothe other of said tie rods, and means interconnecting said frictiondevices so that the release of said one friction device automaticallycauses the ap-.

piication of the other friction device to its drum.

ports extending vertically from said frame, a tie rod oneach side ofsaid bearing supports and extending longitudinall therethrough, a pairof adjacent'drums rotatably carried by said frame within said supports,a friction device associated tending member for exerting pressure onsaid L- shaped plate, a clamp carried by the other end of said seconddrum friction device and associated with the other of said tie rods, alever carried by said clamp for manually releasing said second drumfriction device from its drum, and means interconnecting said frictiondevices so that the release of said one friction device automaticallycauses the application of the other friction device to the drumindependently of said lever.

5. In apparatus of the character described, a base frame, longitudinallyspaced bearing supports extending vertically from said frame, a tie rodon each side of said bearing supports and extending longitudinallytherethrough, a pair of adjacent drums rotatably carried by said framewithin said supports, a friction device associated with one of saiddrums and adapted to be applied thereto to retard rotation of said onedrum, a friction device associated with the second drum to retardrotation thereof, a member carried by and extending vertically of one ofsaid tie rods, an L-shaped plate secured to one end of said second drumfriction device and slidably held on said member, a tension spring onsaid vertically extending member for exerting pressure on said L- shapedplate, a clamp connected to the other end of said second frictiondevice, said clamp being substantially U-shaped and bowed intermediateits ends to surround the other of said tie rods, a lever carried by saidclamp for manually releasing said second drum friction device from itsdrum, and means interconnecting said friction devices so that therelease 'of said one friction device automatically causes th'eapplication of the other friction device to the drum independently ofsaid lever.

6. In apparatus of the character described, a frame comprising endmembers, two parallel tie rods one on each side of said frame connectingsaid end members, a shaft journaled in said end members, a brake drumrotatably mounted on said shaft between said tie rods, a snubber bandextending over said drum between said tierods,

a "manually operable means for releasably connectwith one of said drumand adapted to be applied thereto to retard rotation of said one drum, afriction device associated with the second drum and adapted to bemanually operated to'retard rotation thereof, a band disposed concentricto said second friction device and having pressure contact therewith,means for attaching said band to said first named tie rods, and meansintercom necting said friction devices so thatthe release of onefriction device automaticall causes the application of said band to theother friction device and its drum.

ing one end of said band to'one of said tie rods, and means connectedwith the other tie rod for anchoring the opposite end of said band.

7. In apparatus of the character described, a frame,'two parallel tierods one on each side of said frame, a brake drum rotatably mountedbetween said tie rods, 8, snubber band extending over said drum betweensaid tie rods, means for attaching one end ofthe band to one of said tierods, resilient means connected with the other tie rod for exerting apull on the opposite end of the band, and means on said last named endadapted to be moved in opposition to said resilient ply braking pressureto said drum or to permit free rotation of the drum, a snubber bandmount ed exteriorly of said brake band, and means for contracting orexpanding said snubber band to cause said brake band to trict-ionallyengage or release said drum.

9. In apparatus of the character described, a rotatably mounted brakedrum, a brake band substantially surrounding said drum, means forcontracting or expanding said brake band to apply braking pressure tosaid drum or to permit free rotation oi the drum, a snubber band mountedexteriorly of said brake band, means for automatically contracting saidsnubber band, means responsive to drum rotation in one dime-- tion forexpanding said snubber band, and manual means for disabling said snubberband.

EARL B." LEAR.

